Simplified rotor for fast analyzer of rotary cuvette type

ABSTRACT

A simplified rotor design utilizing two or less cavities per sample analysis station is described. Sample or reagent liquids are statically loaded directly into respective sample analysis cuvettes by means of respective apertures and centripetal ramps communicating with each cuvette. According to one embodiment, a single static loading cavity communicates with each sample analysis cuvette in a conventional manner to facilitate dynamic transfer of liquid from that cavity to the cuvette where mixing of sample and reagent liquids and their photometric analysis take place. Dynamic loading of sample or reagent liquids is provided in another embodiment.

United States Patent [191 Anderson et al.

[ 51 Mar. 25, 1975 SIMPLIFIED ROTOR FOR FAST ANALYZER OF ROTARY CUVETTETYPE [75] Inventors: Norman G. Anderson, Oak Ridge;

Damous D. Willis, Clinton, both of Tenn.

[73] Assignee: The United States of America as represented by the UnitedStates Atomic Energy Commission, Washington, DC.

[22] Filed: July 24, 1973 [.21], Appl. N0.: 382,240

3,798,459 3/1974 Anderson et al7 250/576 Primary Examiner-Ronald L.Wibert Assistant Examiner-F. L. Evans Attorney, Agent, or Firm-John A.Horan; David S. Zachry; Stephen D. Hamel [57] ABSTRACT A simplifiedrotor design utilizing two or less cavities per sample analysis stationis described. Sample or reagent liquids are statically loaded directlyinto respective sample analysis cuvettes by means of respectiveapertures and centripetal ramps communicating with each cuvette.According to one embodiment, a single static loading cavity communicateswith each sample analysis cuvette in a conventional manner to facilitatedynamic transfer of liquid from that cavity to the cuvette where mixingof sample and reagent liquids and their photometric analysis take place.Dynamic load ing of sample or reagent liquids is provided in another[56] References Cited embodiment UNITED STATES PATENTS 3,795,451 3/1974Mailen 23/259 x 8 Clalms, 3 Drawmg Flgures It! l lX/ l 4 I l i g 5 y i1' m I I i PATEHTED MAR 2 5 I975 sum 2 or 2 SIMPLIFIED ROTOR FOR FASTANALYZER OF ROTARY CUVETTE TYPE BACKGROUND OF THE INVENTION Theinvention described herein relates generally to photometers and moreparticularly to an improved rotor for fast analyzers of the rotarycuvette type characterized by two or less cavities per sample analysisstation. It was made in the course of, or under, a contract with theU.S. Atomic Energy Commission.

The general design and operation of fast analyzers of the rotary cuvettetype are generally described in U.S. Pat. No. 3,555,284, issued Jan. 12,1971, to common assignee in the name of Norman G. Anderson. In theanalyzer described in that patent, a central loading disk is providedfor statically receiving sample and reagent liquids prior to an analysisoperation. An annular array of sample analysis cuvettes is disposedabout the central loading disk for receiving the liquids from theloading disk and holding them for photometric analysis. A series of fourserially interconnected cavities are required per sampling station: twostatic loading cavities for receiving sample and reagent liquids, onemixing chamber, and one sample analysis cuvette. Because of spacelimitations, more recently developed miniaturized fast analyzer designsdo not incorporate separate mixing chambers and require only threecavities per sampling station. Typical three-cavity rotor designs areshown in U.S. Pat. No. 3,798,459 issued Mar. I9, 1974, in the name ofAnderson, et al., and U.S. Pat. No. 3,795,451, issued Mar. 5, 1974, inthe name of Mailen.

The radially innermost static loading cavities which are part of eachsampling station limit the total number of sampling stations because ofthe lack of available rotor space at the smaller radius. In the morerecently developed miniaturized fast analyzers identified above, rotorswith diameters of 3.5 inches or less are severely limited wherethree-cavity sampling stations are used.

It is, accordingly, a general object of the invention to provide animproved rotor for a fast photometric analyzer of the rotary cuvettetype characterized by a minimum number of cavities per sampling station.

Another, more particular object of the invention is to provide animproved rotor for a fast photometric analyzer of the rotary cuvettetype having two or less cavities per sampling station.

SUMMARY OF THE INVENTION In a fast photometric analyzer of the rotarycuvette type, a simplified rotor design is provided requiring two orless cavities per sampling station. Sample or reagent liquid is loadeddirectly, by means of a centripetal ramp, into each sample analysiscuvette under static conditions. A single additional static loadingcavity is disposed centripetal to each sample analysis cuvette according to one embodiment. Dynamic transfer ofliquid from the staticloading cavities to respective cuvettes is effected dynamically byconventional means such as radially extending passageways adapted todischarge tangentially into the cuvettes. According to anotherembodiment, static loading of each cuvette is followed by dynamicloading ofa single sample or reagent liquid. Such arrangement permitsthe greatest number of sample analysis stations for any given size rotorand is espe cially suitable in miniaturized rotors where spacerestrictions are greatest.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a top plan view of a rotormade in accordance with the invention.

FIG. 2 is a vertical section view of the rotor of FIG. 1.

FIG. 3 is a top plan view ofan alternative rotor design suitable forcompletely static or static and dynamic loading of sample and reagentliquids.

FIG. 4 is a vertical section view of the rotor of FIG. 3.

FIG. 5 is a bottom plan view of the rotor of FIGS. 3 and 4.

FIG. 6 is a top plan view of an alternative rotor design suitable forcombined static and dynamic loading.

FIG. 7 is a vertical section view of the rotor of FIG. 6.

FIG. 8 is a bottom plan view of the rotor of FIGS. 6 and 7.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to the drawings,initially to FIGS. 1 and 2, each sampling station I (only two ofthirty-two shown) is seen to comprise'a sample analysis cuvette 2 and asingle static loading cavity 3. The rotor 4 is a laminar constructionwith an opaque mid-section 5 sandwiched between top and bottomtransparent plates 6 and 7. As shown, sample analysis cuvettes 2 andstatic loading cavities 3 are conveniently formed by means of holes orslots in opaque mid-section 5 with plates 6 and 7 providing endclosures. Static loading is accomplished by respectively injecting,using a syringe or other suit able means, sample and reagent liquidsinto the sample analysis cuvettes 2 and cavities 3 under staticconditions. Apertures 8 and 9 are provided in top plate 6 to facilitatesuch loading. A ramp 1] is provided on the centripetal side of eachcuvette 2 to permit direct static loading of liquid into the cuvettewithout incurring spillage during rotation of the rotor. Any liquidretained on the ramp following static loading of cuvette 2 isdynamically transferred to the cuvette upon rotation of the rotor.

Dynamic transfer of liquid from each static loading cavity to acorresponding cuvette 2 occurs through passageway 12 which opens at thetop centrifugal side of cavity 3. As shown in FIG. 1, passageway 12discharges tangentially into cuvette 2 to enhance mixing therein ofsample and reagent liquids. A slight outward inclination of each cavity3 aids in the rapid dynamic transfer of liquids from those cavities.Other conventional means for permitting dynamic transfer of liquid fromcavities 3 to cuvettes 2 could be used without departing from theinvention such as the capillary passageway and bubble trap described incopending application Ser. No. 354,041 now U.S. Pat. No. 3,795,45 l, ofcommon assignee.

FIGS. 3, 4, and 5 show an alternative embodiment of the invention intop, vertical section, and bottom views, respectively. Like, thoughprimed, reference numerals are used to designate like features of thealternative rotor embodiment. As in the embodiment of FIGS. I and 2, anannular array of sample analysis cuvettes 2' and static loading cavities3' is provided with passageways 12' joining corresponding cuvettes andcavities. Loading apertures 8 and 9' discharge directly into cuvette 2and static loading cavity 3'. A dynamic liquid systemfis also includedwhich may be used where it is desired to perform a multiplicity of testson a single sample or a single test on a multiplicity of samples,thereby providing a great degree of flexibility to the rotor and makingit amenable to virtually any testing situation. Operation of the rotorusing static loading only is possible in the manner described above inreference to the embodiment of FIGS. 1 and 2.

The dynamic distribution system includes a central distribution chamber15 provided with a serrated periphery 16 which causes liquid fed thereinwhile the rotor is spinning to be substantially equally distributed tothe cuvettes 2'. Radial passageways 17, which have capillary sizedportions 18 to prevent flow from the cuvettes under static conditions,extend between distribution chamber 15 and each cuvette. In operation,either sample or reagent liquids could be statically loaded in thecuvettes, the rotor spun, and respective reagent or sample liquidsdynamically injected to mix with the statically loaded liquids. Asshown, static loading chamber 3' does not extend completely throughopaque mid-section 5 in order that space be available for radialpassageways 17.

Another embodiment, limited in use to dynamic loading of sample orreagent liquids, is illustrated in FIGS. 6, 7, and 8. Asshown in thosefigures, an array of sample analysis cuvettes 2" is provided in a mannersimilar to that of the embodiment of FIGS. 3, 4, and 5. No separatestatic loading cavities are provided, however, since only one liquid isstatically loaded into the cuvettes. A dynamic loading system asdescribed with reference to the embodiment of FIGS. 3, 4, and 5 isprovided with like, though double primed, reference numerals designatinglike features. In operation, sample or reagent is statically loaded inthe cuvettes followed by dynamic loading of respective reagent or sampleliquid through the dynamic loading system. Rotors made in this mannerare limited in number of sample analysis stations only by the number ofcuvettes which can be spaced about their peripheries.

The foregoing description of three embodiments of the invention isoffered for illustrative purposes only and should not be interpreted ina strictly limiting sense. For example, connecting passageway 12extending from the top of each static loading cavity 3, 3' may bereplaced by a capillary passageway and bubble trap in the mannerdescribed in US. Pat. No. 3,795,451. It is intended, rather, that theinvention be limited only be the scope of the claims attached hereto.

What is claimed is:

1. An improved rotor for use in a fast photometric analyzer of therotary cuvette type comprising a diskshaped member of laminatedconstruction with a central opaque disk sandwiched between top andbottom transparent walls, said disk-shaped member defining:

a, circular array of sample analysis cuvettes extending through saidcentral opaque disk for receiving and holding samples and reagents forphotometric analysis;

b. a circular array of outwardly and downwardly extending ramps definingcuvette loading passageways, each of said ramps being in communicationwith the top end of the centripetal side of a respective cuvette in saidarray of sample analysis cuvettes;

c. a circular array of first loading apertures extending through saidtop transparent wall in axial register and liquid communication withrespective ramps in said circular array of ramps for facilitating thestatic loading of liquid in said cuvettes; and

d. means for dynamically injecting liquids into said sample analysiscuvettes.

2. The improved rotor of claim 1 wherein said means for dynamicallyinjecting liquids into said sample analysis cuvettes comprises an arrayof static loading cavities equal in number and disposed centripetal tosaid sample analysis cuvettes, second loading apertures extendingthrough said top transparent wall in register with each of said staticloading cavities and connecting passageways extending between respectivecavities in said array of static loading cavities and said sampleanalysis cuvettes.

3. The improved rotor of claim 2 wherein said diskshaped member furtherdefines a central distribution chamber and a plurality of distributionpassageways communicating between said distribution chamber andrespective cuvettes in said circular array of sample analysis cuvettes.

4. The improvement of claim 3 wherein each of said distributionpassageways intersects with adjacent distribution passageways to form aserrated periphery about said distribution chamber.

5. The improvement of claim 3 wherein each of said distributionpassageways has a capillary-sized portion.

6. The improved rotor of claim 1 wherein said means for dynamicallyinjecting liquids into said sample analysis cuvettes comprises a centraldistribution chamber and a plurality of distribution passagewayscommuniabout said distribution chamber.

8. The improvement of claim 6 wherein each of said distributionpassageways has a capillary-sized portion.

1. An improved rotor for use in a fast photometric analyzer of therotary cuvette type comprising a disk-shaped member of laminatedconstruction with a central opaque disk sandwiched between top andbottom transparent walls, said disk-shaped member defining: a, circulararray of sample analysis cuvettes extending through said central opaquedisk for receiving and holding samples and reagents for photometricanalysis; b. a circular array of outwardly and downwardly extendingramps defining cuvette loading passageways, each of said ramps being incommunication with the top end of the centripetal side of a respectivecuvette in said array of sample analysis cuvettes; c. a circular arrayof first loading apertures extending through said top transparent wallin axial register and liquid communication with respective ramps in saidcircular array of ramps for facilitating the static loading of liquid insaid cuvettes; and d. means for dynamically injecting liquids into saidsample analysis cuvettes.
 2. The improved rotor of claim 1 wherein saidmeans for dynamically injecting liquids into said sample analysiscuvettes comprises an array of static loading cavities equal in numberand disposed centripetal to said sample analysis cuvettes, secondloading apertures extending through said top transparent wall inregister with each of said static loading cavities and connectingpassageways extending between respective cavities in said array ofstatic loading cavities and said sample analYsis cuvettes.
 3. Theimproved rotor of claim 2 wherein said disk-shaped member furtherdefines a central distribution chamber and a plurality of distributionpassageways communicating between said distribution chamber andrespective cuvettes in said circular array of sample analysis cuvettes.4. The improvement of claim 3 wherein each of said distributionpassageways intersects with adjacent distribution passageways to form aserrated periphery about said distribution chamber.
 5. The improvementof claim 3 wherein each of said distribution passageways has acapillary-sized portion.
 6. The improved rotor of claim 1 wherein saidmeans for dynamically injecting liquids into said sample analysiscuvettes comprises a central distribution chamber and a plurality ofdistribution passageways communicating between said distribution chamberand respective cuvettes in said circular array of sample analysiscuvettes.
 7. The improved rotor of claim 6 wherein each of saiddistribution passageways intersects with adjacent distributionpassageways to form a serrated periphery about said distributionchamber.
 8. The improvement of claim 6 wherein each of said distributionpassageways has a capillary-sized portion.